Crystal structure of 4,5-di­nitro-1H-imidazole

G Kenneth Windler; Brian L Scott; Neil C Tomson; Philip W Leonard

doi:10.1107/S2056989015013432

. 2015 Aug 6;71(Pt 9):o634. doi: 10.1107/S2056989015013432

Crystal structure of 4,5-dinitro-1H-imidazole

G Kenneth Windler ^a, Brian L Scott ^b, Neil C Tomson ^b, Philip W Leonard ^a,^*

PMCID: PMC4555365 PMID: 26396875

Abstract

The title compound, C₃H₂N₄O₄, forms crystals with two molecules in the asymmetric unit which are conformationally similar. With the exception of the O atoms of the nitro groups, the molecules are essentially planar. In the crystal, adjacent molecules are associated by N—H⋯N hydrogen bonds involving the imidazole N—H donors and N-atom acceptors of the unsaturated nitrogen of neighboring rings, forming layers parallel to (010).

Keywords: crystal structure; 4,5-dinitro-1H-imidazole; hydrogen bonding

Related literature

For background to imidazoles and the title compound, see: Windaus & Vogt (1907 ▸); Cooper (1996 ▸); Epishina et al. (1967 ▸). For the preparation, see: Novikov et al. (1970 ▸). For similar structures, see: Parrish et al. (2015 ▸); Windler et al. (2015 ▸). graphic file with name e-71-0o634-scheme1.jpg

Experimental

Crystal data

C₃H₂N₄O₄
M _r = 158.09
Monoclinic,
a = 11.4797 (9) Å
b = 8.8205 (7) Å
c = 11.802 (1) Å
β = 107.827 (1)°
V = 1137.65 (16) Å³
Z = 8
Mo Kα radiation
μ = 0.17 mm⁻¹
T = 100 K
0.12 × 0.06 × 0.06 mm

Data collection

Bruker D8 Quest with CMOS diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▸) T _min = 0.971, T _max = 0.995
25837 measured reflections
4868 independent reflections
4216 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.118
S = 1.60
4868 reflections
211 parameters
All H-atom parameters refined
Δρ_max = 0.54 e Å⁻³
Δρ_min = −0.33 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▸); cell refinement: SAINT (Bruker, 2009 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸), Mercury (Macrae et al., 2008 ▸) and PLATON (Spek, 2009 ▸); software used to prepare material for publication: CHEMDRAW Ultra (Cambridge Soft, 2014 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989015013432/zs2338sup1.cif

e-71-0o634-sup1.cif^{(21.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015013432/zs2338Isup2.hkl

e-71-0o634-Isup2.hkl^{(238.5KB, hkl)}

Click here for additional data file.^{(2.4KB, cdx)}

Supporting information file. DOI: 10.1107/S2056989015013432/zs2338Isup3.cdx

Click here for additional data file.^{(2.7KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015013432/zs2338Isup4.cml

Click here for additional data file.^{(1,002.6KB, tif)}

. DOI: 10.1107/S2056989015013432/zs2338fig1.tif

The molecular structure of the title compound with atom labeling. Ellipsoids are drawn at the 50% probability level and the hydrogen atoms are drawn as spheres of arbitrary size.

Click here for additional data file.^{(1.6MB, tif)}

b . DOI: 10.1107/S2056989015013432/zs2338fig2.tif

A crystal packing diagram for the title compound viewed along the b axis. The N—H⋯N hydrogen bonds are shown as dashed lines.

CCDC reference: 1412685

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
N3H2N7ⁱ	0.90(2)	1.96(2)	2.836(1)	163(2)
N8H4N4ⁱⁱ	0.92(2)	1.89(2)	2.807(1)	179(3)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This work was supported by the National Nuclear Security Administration Science Campaign 2 and performed at Los Alamos National Laboratory under DE-AC52-06 N A25396. LA-UR-15-23929

supplementary crystallographic information

S1. Comment

In addition to more mundane uses as pharmaceuticals (Windaus & Vogt, 1907), imidazoles make quality backbones for energetic materials (Epishina et al., 1967) because of their nitrogen content. The dinitro-bearing title compound, C₃H₂N₄O₄, is of interest because of its better oxygen balance (Cooper, 1996), contributing to its effectiveness as an explosive. To better understand the nature of explosive sensitivity as it relates to intermolecular forces, the title compound (Fig. 1) was of interest for comparison with other imidazoles previously studied (Parrish et al., 2015; Windler et al., 2015).

In the title compound, the two independent molecules (A, defined by C1–N3 and B, defined by C4–N7) in the asymmetric unit (Fig. 1) are conformationally similar with the nitro groups being variously rotated out of the imidazole planes: in A [torsion angles N3—C1—N1—O2, -174.29 (9)° and N4—C3—N2—O3, 163.63 (7)°] and in B [torsion angles N7—C4—N5—O6, 156.95 (8)° and N6—C6—N6—O7, 163.63 (7)°].

In the crystal, intermolecular N—H···N hydrogen bonding interactions N3—H···N7 and N8—H···N4 between the A and B molecules (Table 1), generate layered structures lying roughly parallel to (010) (Fig. 2).

S2. Experimental

Caution! The title compound is an explosive and should only be handled with appropriate safety equipment in small quantities by an experienced explosive handler.

The title compound was prepared by literature methods (Novikov et al., 1970). Crystals were obtained by slow evaporation of a concentrated solution in ethyl acetate.